[rjparjay]

So I just did a amber ale on friday using US-04. I noticed something today though. I checked the hydrometer reading and it has fully fermented from an OG of 1.049 to 1.014. However, there is a slight sour smell and slight sour aftertaste. I'm thinking this will probably clean up because I know it hasn't been very long but I can't believe it's been infected after a healthy pitch and only 4 days. I should also note that there are no visual signs of infection.

Long story short, does US-04 create sour flavors when fermented low or could this be something else?

[hooter]

Long story short, does US-04 create sour flavors when fermented low or could this be something else?

Not that I've noticed.  S-04 ferments fairly clean, especially at that temp.  I once accidentally fermented way too warm with that yeast which produced a very fruity, funky beer bordering on Belgian like, but no sourness.  Of course, it's way too early to even be tasting this beer and it will more than likely fade over time.  If it's still sour after a couple weeks then we'll talk.

[rjparjay]

I definitely agree that it's too early to be tasting it but I just moved into a new apartment and my other beer also has a strange taste and I was seeing if they both had it or if it was something else altogether. It seems to be something entirely different but then I discovered the sour taste. It's so minimal that I really think it will get cleaned up after primary and secondary plus I'll be dryhopping it so it will mask most of it. I just thought it was weird because I've never experienced that before.

[Joe Sr.]

I don't believe I've ever used US-04, but I have noticed over the past couple of years that I get a tart/sour flavor when I use dry yeast.

From my tasting notes, I have had this flavor with US-05, Nottingham and Windsor (IIRC).

For the time being, I'm moving away from dry yeast as much as possible.

There are a couple other threads on the tart flavor.

On the flip side, I know that many many people use dry yeast and don't get this flavor.

[Alewyfe]

I have used SO-4 at a variety of temps and always detect an initial taste of sourness in the green beer.
Once the yeast completely drops out, I no longer can pick up that taste. I'm guessing in a couple weeks it will be fine. RDWHAHB

[AmandaK]

I'm with Diane, it's a bit too green. Nothin' a little time can't help!

[rjparjay]

I have used SO-4 at a variety of temps and always detect an initial taste of sourness in the green beer.
Once the yeast completely drops out, I no longer can pick up that taste. I'm guessing in a couple weeks it will be fine. RDWHAHB

Thanks a lot! I kind of figured it would clear up but wasn't sure. I definitely agree its too early to be sampling it but for certain reasons I had to.

[bluesman]

I've gotten a slight tartness from this yeast in very young beer.  The yeast should clean this up in due time as the beer begins conditioning stage.  Let the beer condition at room temp for several days until the beer is bright then check the gravity and cold crash.